I've become intrigued with the Onno pipe, and read a fair number of threads on the topic, so I understand the basics. 2 pairs of mics, connectors touching on inner omnis, 10' spacing on outer omnis, 45° out. Schoeps MK-2h capsules recommended (in fact invented for Onno), although he liked the dpa 4060 as well. I've read that it needs to be carefully placed in order for the image to come in to "focus". If I use this, I will have time to fine tune placement, but won't have time to start from scratch, and what I haven't been able to glean is what a good starting position would be. Does this pipe need to be boomed over the conductor like a 1m pair for Decca recording, or can it reside behind the podium? How high up?

Thanks, I look forward to your insights.

I think you've confused two different 'Onno' rigs.

The 'Double AB' 'Onno 'Pipe' was used almost exclusively with 4006's, not 4060s; that was the much later (post retirement) "Onno AB' that was a single closely-spaced pair.

I think I've read all the threads on here about it, and I don't recall anyone saying he ever used Schoeps' on the dual-pair 'Pipe',

I wish @ mpdonahue had provided more detail on his comment that it is hard to position for it to 'come into focus'. I haven't found it to be any more difficult to place than any other omni array.

I find it works best where would place an omni pair in a given situation. That is, it depends on the particular degree of 'roominess' one prefers; because it doesn't usually entail the use of outriggers, I tend to place it a bit higher and further back than one would use a full 5-mic Decca Tree.

Though it's stated that the mix of the two pairs is equal, I prefer the 10' pair down 2-3dB; on headphones it sounds less 'phasey', but doesn't compromise it's lushness on loudspeakers.

Just to be clear, the mics are 45 degrees out from center, so a total of 90 degrees from each other.

A rough idea of height (in an instance of it's use by Soundmirror for the BSO) can be seen in the attached photo. Download it so you can see it full size. Ignore the mic hanging straight down near the center of the bar; it's not part of it.
The ONNO Bar at Symphony Hall, Boston

Thanks! I knew that the 4060 thing was post retirement, I didn't know that it wasn't the pipe array.

I can't find where I found the mk2h thing. If I do it, the first time will be with mk5 caps, because that is all that I have 4 of at the moment.

Being able to place it higher and further back would be good, especially if it can be behind the podium--then I don't have to use a boom. I can't fly mics at this venue. Also, the conductor has a tendency to make noises, and if the array is above and behind him rather than just to the side, those noises may less noticeable.

Of course, it needs to be a room where omnis work well; of which there are fewer and fewer these days (in the US, anyway).

I had good luck in October when I recorded in this hall with a 4 mic (2 mains + outriggers) Mk2h with 40mm APEs for mains, Mk21 for outs. I'm just on a fact finding mission regarding the Onno Pipe--sounds like it might be worth a try.

Everyone who records Classical owes it to themselves to explore it extensively; it really sounds like nothing else, in it's equal effectiveness for headphone and loudspeaker presentation.

The pic in the thread shows it as flown from the ceiling…. I wonder if it is wise to contemplate how it could be safely raised on a single stand behind the conductor. I would expect some flexing of the bar at 10 foot width. If it were supported by diagonal struts for each side arm, that could help maintain stability?

I use lightweight glass epoxy tubing (three pieces; the outer two of smaller dia. to fit inside the center section), and simply suspend the center mic pair on extensions that compensate for the flex, so that they align horizontally with the outer pair.

https://www.tapplastics.com/product/...WbhFcHjl36YbfF

The mic mounts are Sabra-Som; also very lightweight.

With compact-head mics like Rode NT6 and Schoeps CMC 1 L, it's quite stable on a single stand; the only way I've ever used it.

If there was a way to incorporate the typical twist-to-lock telescopic fishing rod (pole) mechanism between the inner/outer tubes as you’ve described above, you’d have a secure and repeatable length extension for each arm…but I’ve never seen such a thing advertised?

My preferred support method would be 2 x round base mic stands, either side of the conductor podium, each supporting the first 1/3 of the entire pole. You’d get much less (if any) flexing of the pole, due to its 1/3 and 2/3 (of total length) dual supports.

Also, for video purposes, the conductor can take their bows to the audience without hitting forehead on central mic stand, and provides a clear line of sight for cameras.

Only downside is it takes 2 people in unison to raise and lower the stands…but if you’re recording a chamber group or orchestra, there’s never a shortage of team-centric helping hands.

Another two-stand approach would be a slightly less than 5' tube on each stand, with mics at each end; then just place them so that the two inside mics are the small AB distance apart.

If I recall Mark Donahue’s description correctly, it was 15-20 cms spacing for the inner omni pair, each mic angled out 45* (same as outside pair) ?

Edit: this might be of alternative interest, although it employs spaced centre cardioids…not omnis ie OCCO

https://www.seeingsound.com/occo-ste...ding-technique

Both pairs 45 degrees out from center, so 90 degrees to each other (same as the Faulkner 4-mic).

I'm aware of two statements he's made about the spacing of the middle pair: 25 to 30cm, and his description of the 4006s being angled 90 degrees, with the XLRs touching at the back (which would put the capsules much further apart than 15-20cm).

In various publications, it's been stated as 1', but on here Mark has said he thought that was too far apart.

I've been using 10-12" and haven't found the spacing to be terribly critical.

Another interesting comment he's made is that Scholtze always aimed the four mics straight out, not aimed down. I've assumed this is to give a little added sparkle to the back of the orchestra, while reducing stridency in the first rows of strings.

Has anyone done comparative checks on the relative strength, weight and (probably most significantly) the flexure properties of fibreglass epoxy, acrylic and carbon fibre options, as materials for mic support duty ?

I’m guessing wall thickness and overall diameter of tubing will be the main determinant, with material properties coming in second ? A solid tube for the final (thinnest) section might also reduce bending ?
We could use a materials scientist to weigh in here with facts on the physical properties of these various tube/rod types

I finally found the reference to Onno and the Schoeps mk2h, 2nd post in this thread:
Schoeps MK-2 or MK-2h ? ? ? ? ? ?

As far as rigging, I have come across 16mm (really close to 5/8") rods that thread together. With a stable, sand bagged base I don't think I'll be too worried about it. I'll try to get a picture together when I get a chance.

As regards rigging I’ve found the Selens Magic Ball with multiple threaded holes to be useful for both Decca Tree and other arrays…you get the option for multiple arm angles. There are 2 versions available….a spherical blue one and a hemisphere red.

The thread holes are 3/8” and hence you can buy various lengths of threaded stainless steel rod from hardware stores and cut to suit. I add black heatshrink to the rods, leaving 1-2” bare at each end, as the rod threads are sharp and rough on your hands.

https://www.aliexpress.com/item/33015767794.html

https://www.aliexpress.com/item/4001047599822.html

Threaded end carbon fibre or fibreglass rods would work equally well with lighter weight, but more flexion (depending on length and mic weight)

Just remember when using 3/8" UNC threaded rod that the working load is around 600 lbs (270 Kg). The longer the rod, the more leverage on the threads. I might be tempted to do some back of the envelope calculations if using heavy LDC mics (e.g. MK 50) on a Decca tree using a Manfrotto/Selens dado ball as the central connector. Be especially careful if brass threads are in the mix. That said, I agree that dado balls are very useful when creating various arrays.

PS: I realize we are talking Onno pipe with SDC here. Just a caveat.

Yes, definitely only SD mics in the Dado/Selens hub context with 3/8” rod (of any material)…and that also extends to really lightweight mic suspension mounts, low weight xlr connectors and mouse-tail thin mic cable, as all these factors can add mass/leverage !

The only concession I might make would be to add a 40mm diameter wooden APE sphere…when needed.

When working with carbon fibre rods and tubes, can anyone report whether using heatshrink (applied with a heat gun) is likely to damage or weaken the carbon fibre structure...or is it quite heat resistant ?

Carbon fiber itself is stable to about 2900°F. Epoxy, which I assume is what is used to hold it together is only good to 150-300°F for short periods of time before it begins to distort, and I would assume weaken. That said, I don't think that applying heat shrink tubing should overly stress out the carbon fiber tube. You might reach surface temps of 150°, but I wouldn't think there would be much heat penetration.

Thanks jheath...I was specifically thinking of the Rode Micro Boompole Pro, if you're familiar with that thin diameter threaded-end rods system ?

I own three of the Røde poles! I usually use 2 sections at a time for outriggers and woodwind spots. what are you doing with the shrink tubing?

I’ve added a piece of 3/8” steel thread to one of the ends and an irrigation T-piece (with mic holder) in the centre….so it’s now an unlikely 72cm ORTF + AB bar. Yes, crazy, I know…I’ll add a photo soon…better than 1000 words…!

The heatshrink will stop the boompole from twisting inside the T-piece better than wrapped insulation tape…

I look forward to seeing it! I don't think the heat shrink application will deteriorate those rods at all.